Prior art cleaning devices are known comprising self-propelled apparatuses which, after being immersed in a swimming pool, may move on the bottom and on the walls of the swimming pool for cleaning using brushes and a detritus suction circuit.
These devices have turbines which can apply a downward thrust, for maintaining the contact between the device and the surface on which it moves. The inside of the device houses a collection filter which retains all the impurities sucked in.
The self-propelled device is also internally equipped with an electric energy supply unit, designed to supply electricity to electric and electromechanical devices present in the self-propelled device, for example the motors designed to drive the wheels and the turbines, the electronic circuits for detecting impurities, processing the data detected and controlling the various motors, etc.
When the power supply unit, normally a battery or a battery pack, is almost flat, the self-propelled device automatically goes to a recharging base, where the power supply unit can be recharged so that, when a predetermined time has elapsed, it can continue to power swimming pool cleaning work.
There are currently various techniques for recharging the power supply unit mounted on board the self-propelled device.
One of these techniques uses an inductive coupling between a first inductive element which is part of the recharging base, and a second inductive element which is mounted on the self-propelled device and connected to the power supply unit to be recharged.
In this way, when it is the battery recharging condition, the self-propelled device is automatically positioned at an electromagnetic field generated by the first inductive element, to guarantee the transfer of electric energy towards the second inductive element. For this reason, the recharging base is positioned in an area of the swimming pool which can be easily reached by the self-propelled device, normally close to the bottom. In particular, the recharging base is often constrained in a lower area of a side wall of the swimming pool, in such a way as to generate a magnetic field at the bottom and in general in the areas involved in the cleaning operations performed by the self-propelled device.
The base constrained to the wall of the swimming pool is also coupled to a pair of electric cables which are electrically connected to the first inductive element, allowing a predetermined current to flow in the latter, so that power can be transferred to the second inductive element and therefore the battery of the self-propelled device can be recharged.
In general, the electric cables are also constrained to the side wall of the swimming pool and run, in view, from the recharging base (positioned in a lower area) to the outer edge of the swimming pool, where they are suitably connected to the domestic mains.
There are also prior art concealed electric connections extending within the side wall of the swimming pool. In this case, the recharging base is constrained to the side wall of the swimming pool at electric terminals extending from the wall itself.
However, the prior art apparatuses described above have a major disadvantage mainly linked to maintenance operations on the recharging base.
In fact, to work on the first inductive element, it is necessary to operate in the swimming pool to remove the recharging base, with the consequent disadvantages in terms of practicality, often if the water is not removed from the pool to avoid expensive emptying operations.
Moreover, to perform operations for substituting the electrical connections it is necessary to remove from the swimming pool both the base containing the first inductive element and the electric cables suitably constrained to the side wall or, even worse, built into the wall.
Such maintenance operations are therefore complicated and particularly expensive.